This study, based on the Pulmonary Embolism Response Team (PERT) Consortium Registry, aimed to understand the management and outcomes of patients with high-risk pulmonary embolism (PE). It found that high-risk PE patients were more often treated with advanced therapies compared to intermediate-risk patients. Patients with haemodynamic instability experienced high rates of in-hospital mortality and major bleeding. Factors such as vasopressor use, extracorporeal membrane oxygenation, identified clot-in-transit, and malignancy were linked to increased in-hospital mortality. Particularly, catastrophic PE patients showed even higher mortality rates. This comprehensive analysis highlights the severe impact and treatment challenges of high-risk PE.